Remove the need for the submodules

WIP.

I realized that the submodules can't be readily uninstalled as other modules depend on them :-\

I updated the build script to generate the YAML file automagically.

Sorry, this is the correct patch.

+1 to this, I found it terribly confusing to need to install apparently empty modules

I agree that it is confusing that it's not statically defined, but are you sure it's actually broken?

I tested with runtime library definitions for jquery_ui_slider and it is properly defined:

> $discovery = Drupal::service('library.discovery')

> array_keys($discovery->getLibrariesByExtension('jquery_ui_slider'));
= [
    "slider",
  ]

That was IMHO exactly the goal of the change, to deal with the removal of those libraries in core but make it backwards compatible.

While this makes sense, it is definitely an actual API change then and would need to be a new 2.x major version.

Which part would count as an API change - the fact that all of the libraries would be available, not just the ones available because of a submodule?

Libraries are namespaced by module, so instead of jquery_ui_slider/silder, it will now be in the jquery_ui namespace. Your current names are actually repeating, so it would be jquery_ui/jquery_ui_slider (You probably want to name them just "slider" for example.). That will break all modules depending on a specific library.

So I wonder if I could leverage the existing alter hook to modify the names? Let me look into that.

You can only alter by module, so I don't think so?

To be clear, I'm not saying this is bad. I'd love to have fewer dependencies around jquery_ui modules. But it is an API change, and the current behavior of 8.x-1.5+, as weird and confusing as it may be (some documentation would probably help a lot with that), is IMHO not.